Mechanics

HAD A CODE P0171 ONLY AND REPAIRED VACUUM LEAK. WHAT COULD KEEP CAUSING A SKIP OR LUGGING TYPE FEELING DRIVING THE VEHICLE AFTER REPAIRS TO LEAK AND C

2003 Ford F-150 • 177,000 miles

I have a 2003 Ford F-150 and just recently it started running rough like it wanted to stall out at stops and had a skipping type feeling while accelerating. I had a parts store check the check engine soon light and a P0171 code appeared. I found a vacuum leak at rear of intake at the elbow on the pvc valve hose. I replaced the hose and cleared the computer and it still has the lugging or skipping feeling while accelerating.I would appreciate some help if you don't mind on what you guys think it can be. I don't know if cleaning the maf sensor will help or not, truck was running great until the vacuum leak started and I really do not have the money because I have been out of work for over a month because I was diagnosis with terminal cancer and had my left kidney removed and cancer is in my right one as well but just has started attacking it and there is no cure for my type of cancer. Sorry to bother you guys with my personal problems but any help would be very much appreciated because I'll be doing this myself. Thanks!
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Buckbass
May 2, 2012.




It sounds like the plugs are worn out. Pull one and check.

Sorry for your condition.

Good job on the elbow hose, very common failure for those motors

Roy

The plugs may have around 30k on them had it tuned up June or July of 2010.

Tiny
Buckbass
May 2, 2012.
Did you use platinum plugs?

Roy

I'm not sure they were suppose to have they cost about $8 or 9 bucks a piece. I have been reading about people with the same leak and after the repair vehicle still running rough and they cleaned the MAF sensor and supposedly the vehicles ran great again. I can't believe that after repairing the vacuum leak it still feels like it did with the leak but not as bad. Does the computer take some time to relearn the mixtures after something like this, I've even heard this. Thanks!

Tiny
Buckbass
May 2, 2012.
YES IT WILL TAKE SOME TIME TO ADJUST THE FUEL TRIM READINGS. I DONT THINK THATS YOUR PROBLEM. SECONDARY IGNITION PROBLEMS ARE BIG. ON A FORD YOU MIGHT HAVE A HARD TIME FINDING A MISS FIRE COUNTER WITH A SCANNER. BUT YOU COULD HAVE SOME ONE SCAN IT IN MODE 6 AND SEE WHICH CYLINDER ARE COUNTING MISS FIRES. THEN SWAP THE COILS TO SEE IF IT MOVES

Djcl
May 2, 2012.
Yes, you can clear the memory by removing the battery cable for about 10 seconds and installing. It may not idle right away till it relearns but it may make it somewhat better.

Never a believer about cleaning maf. The carbon is burned into the wire and no cleaner can remove it. If it is out of range, it needs to be replaced.

I still think your issue is secondary ignition.

Roy
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I know a coil can go out just like that and some will misfire or breakdown when going out. I guess I can unplug cylinders to see if idle changes any in the morning and go from there. I just ran out and drove it maybe about a mile and the SES light came on. I'm suppose to go to the doctors tomorrow had to cancel appointment today because of truck. I want to thank you for your time and advice and sorry about donating I'm in a heck of a bind here with everything happening all around the same times.

Tiny
Buckbass
May 2, 2012.
Can a coil cause a P0171 code? I'm not sure if they were replaced I can't remember. The number 3 plug blew out of the cylinder head like so many Fords do back in 2010 when I had them install the new plugs because it had been around 75k then and I know they were the platinum plugs or 100k plugs because I had it tuned up then and I think that was around 100k on the truck.

Tiny
Buckbass
May 2, 2012.
No, the coil will not cause the 171.

Hope we helped you out a little.

Good luck

Roy

Thanks

Tiny
Buckbass
May 2, 2012.

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